How to Choose an LCD Module in Seven Decisions

Specifying a display is seven decisions, and their order matters more than any single one of them. Size and interface come first because they constrain everything downstream and are the most expensive to change late. Quantity comes last but decides which of the earlier answers you can afford. Work through them in this order and a supplier can quote you in one round.

Written by the Junxian applications engineering team. Figures quoted for “our models” are calculated from the 103 models on this site that carry a full parameter set, so they change when the catalogue changes.

The seven decisions, in order

Send us these seven and you get a firm quotation in one round instead of three.

1-2. Size and interface: the two you cannot change late

Size is set by the enclosure opening, so send the opening dimensions rather than a diagonal - a 7-inch panel from two makers can have different outlines and different active-area positions. Interface is set by your processor: if it has a display controller, use what it drives; if it does not, use a serially driven small panel or a smart module that takes commands. Both of these are laid into the mechanical design and the carrier board, and both cost a respin to change afterwards.

Diagonal size and resolution alone do not tell you the physical width and height, or how sharp the UI will look - enter your numbers below to check both before you commit to an enclosure cutout.

3-4. Resolution and brightness: the two people over-specify

Higher resolution costs interface bandwidth, memory, power and money, and above a certain density the operator cannot see the difference at working distance. Pick the resolution your UI needs. Brightness follows where the display physically sits: 200-300 cd/m² indoors, 350-450 near windows or under a canopy, 500 and up in direct sun - and remember that the brightness you specify is what you pay for in power and backlight lifetime.

5-6. Touch and temperature: the two that hide surprises

Touch is not a yes/no question: gloves, wet hands, stylus use and cover glass thickness change the whole stack, and they are cheap to specify up front and expensive to retrofit. Temperature is about the coldest and hottest the display actually sees at its mounting position, not the ambient in the room, and about whether it has to start cold or only run cold.

7. Quantity: it decides which answers you can afford

Annual quantity sets the MOQ tier and whether tooling makes sense. An honest forecast is worth more than an impressive one - a price quoted against a volume you do not reach helps nobody. Below 1,000 pcs, adapting an existing panel is almost always the better commercial route, and often technically identical.

What is available at each tier

Before deciding, it helps to see the depth of what already exists - the more models in a category, the more likely your requirement is met without tooling:

Catalogue MOQ is the same 100 pcs across categories - the tier is set by whether glass has to be tooled, not by product type.

The enquiry that gets a firm quotation in one round

Size (with the enclosure opening drawing), resolution, interface, touch requirement including glove use, brightness or the physical location, operating temperature range at the display position, and annual quantity. Add a photo of the current display if you are replacing one. Everything else - driver IC, FPC, connector, backlight colour - we can propose once those seven are known.